Shorter than Cunningham's Encyclopedia of Crystal, Gem & Metal Magic but also more colloquial and readable, this work predates Cunningham by more than 10 years (the oriinal was published in 1975).
The first two chapters cover, in general terms, history and use of gemstones. This is followed up by a 'Gem and Stone Personality' quiz, based on the gemstones you personally identify with. Following this are chapters on the healing powers of gemstones, wearing gemstones, and 'identifying' stones (that is, the mineralogical qualities of stones).
The central section, the A-Z of Stone Power, profiles 48 stones, including details on different agates and quartzes, as well as petrified wood, bone & ivory, shells, and scarabs. Brief mineralogical information and folklore and historical uses are mixed with recommendations for why and how to use the stone. The author's chatty tone implies an in-depth working familiarity with all the stones profiled.
Further notes include stone/metal combinations, alternative ways to use them, color properties, and charts of recommendations for professions, problem solving, performance aids, attitude balancing aids, and a list of gems of the ancients. There are two color plates showing a variety of gemstones, and an excellent one page list of references for further reading.
Though this sounds dense, each of the chapters is very short and readable. Mella is generally new-agey, but not as wifty as Cunningham (she doesn't preach against pearls, for instance, despite the deaths of oysters). Mella does a much better job than Cunningham with the agates, also. I don't agree with her on the best stone/metal combinations, but they are in line with traditional recommendations. I also wouldn't be bound by her charts on what does what, but use them as a guide for exploring the use of stones. I actually quite like the personality test as a way to 'get to know' stones, also.
In general, this is an excellent work for the beginner, though Cunningham's chapter on getting to know the stones would also be useful to the novice. It is a friendly, chatty book, full of practical (rather than mystical) suggestions, though it is a little bit like getting magickal advice from Barbara Cartland.